Cable tray



J. MADL, JR 3,112,093

Nov. 26, 1963 CABLE TRAY Filed Sept. 7. 1.960

IN V EN TOR. OSEPH/Zfll, JQ. 47'7'0E/Vf United States Patent 3,112,093CABLE TRAY Joseph Madl, Jr., Arcadia, Calif., assignor to UnistrutProducts Company Filed Sept. 7, 1960, Ser. No. 54,436 Claims. (Cl.248-68) This invention relates to a cable tray or cable ladder and hasfor an object to provide an efficient and improved item of the characterreferred to for supporting cables, pipes, wiring, conduit, tubing andother elongated items that are provided in buildings and otherstructures.

Another object of the invention is to provide a cable tray that, whilestrong, is inexpensive to manufacture and has considerable flexibilityof use in a wide range of installations.

A further object of the invention is to provide a cable tray that,because of its ease and facility of assembly, may be stocked in knockdown or separated form, thereby greatly reducing the inventory that isordinarily required and yet allowing rapid filling of orders for cabletrays varying considerably in size and proportion.

Since cable trays have a depth dimension that varies between three andsix inches, longitudinal center-to-center spacing of the cross-channelmembers that may be three, six, twelve and eighteen inches, and widthsbetween six and twenty-four inches varying in increments of two, three,four and six inches, the stock or inventory of a distributor of priorcable trays is necessarily unduly large in order for him to be inposition to fill orders without special handling and the attendingadditional expense.

The components of the present cable tray structure, because of ease ofassembly thereof, may be stocked as individual items, in a large rangeof size, and, upon receipt of an order therefor, assembled as desiredfrom a numerous yet low cost inventory.

Further, the knock down inventory is space-saving in relation to themore bulky pre-assembled cable trays.

This invention also has for its objects to provide such means that arepositive in operation, convenient in use, easily installed in a workingposition and easily disconnected therefrom, economical of manufacture,relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novelcombinations and arrangements of parts, which will more fully appear inthe course of the following description, which is based on theaccompanying drawing. However, said drawing merely shows and thefollowing description merely describes preferred embodiments of thepresent invention, which are given by way of illustration or exampleonly.

In the drawing, like reference characters designate similar parts in theseveral views.

FIG. 1 is a broken longitudinal side elevational view, partly inlongitudinal section, of a cable tray according to the presentinvention.

FIG. 2 is an enlarged and broken cross-sectional view as taken on theline 22 of FIG. 1.

FIG. 3 is a similar cross-sectional view of one side of the tray astaken on line '3-3 of FIG. 1.

FIG. 4 is a fragmentary longitudinal sectional view as taken on the line4-4 of FIG. 1 and drawn to the scale of FIG. 1.

FIGS. 5 and 6 are fragmentary and enlarged cross-sectional views ofmodifications.

The cable tray that is illustrated comprises, generally, side members10, cross members 11 and 12, means 13 to connect the ends of the members11 and the side members 10, means 14 interengaging the ends of members12 and the side members 10, and splice means 15 to connect the adjacentabutted end of the trays. The above "ice generally described cable trayis advantageously made of sheet steel or aluminum.

The side members 10 are alike, each comprising a side wall 24), upperoutwardly and downturned reinforcing flange 21, and a lower reinforcingportion shown in FIGS. 1, 2 and 3, as an inturned flange wall 22, inFIG. 5, as an outturned flange 23, and in FIG. 6, as an outturned rolledbead 24. In any case, each side member 10 may be thinwalled, yet strongfor the intended purpose.

The cross members 11 and 12 are essentially alike in the portion thatspans between the sides 10'. While they may have a diflferentcross-sectional form, for instance, angle section, the same, as shown,are preferably of channel cross-section with side flange walls 25 and aconnecting top wall 26. Regardless of the crosssectional shape of themembers 1 1 and 12, the same are disposed with their top walls 26 up andserving as smooth support surfaces for cables, wiring, etc.,longitudinally disposed in the trays. Said members preferably extendbetween the lower portions of the sides 10' to provide for maximumeffective height of the sides.

The means 13 connects the ends of the cross members 11 and the sides 10,said means preferably comprising elongated extensions 27, one from eachflange and top wall of each said member, a set of slits 28 punchedthrough each wall 20 in such relation as to receive the extensions 27,and tight crimps or beads 29 formed on the ends of extensions and inclinching engagement with the outsides of the side members 10. Saidslits 28 are punched in flange walls 22 in cases where said walls extendsubstantially above the lower edges of the side walls 20.

With the extensions 27 straight, the same are entered into slits 28 toprotrude as shown by the dot-dash lines of FIG. 2. Then, as theseextensions are formed into heads, the same draw the sides 14} into tightengagement with the ends 39 of the members 11 and effect a rigidassembly of sides and cross members.

The means 14 locate the ends of cross members 12, the same comprisingextensions 31 similar to, but substantially shorter than, the extensions27. The sides 10 are provided with slits 28 as above described toreceive said extensions 31. It will be realized that the cross members11 and 12 are all assembled into place before the extensions 27 of themembers '11 are beaded over. Thus, the members 12 serve as side spacersas well as supports while members 11 constitute connections for thesides 11. It is a matter of choice how many connector members 11 areused for each tray, two being the minimum for good construction, theintermediate members 12 filling in between the connector members,accordingly.

FIG. 1 shows each set of slits 28 in use to receive the extension 27 or31, as the case may be. It will be realized that not all the slitsprovided need be put into use. Thus, trays may be assembled withdifferently spaced transverse support members, according to lead out andother requirements. It will also be realized that the same cable traymay have unevenly spaced cross members, as desired, for a particularcondition, the flexibility of the present construction lending itself tovariations in the assembly of the components. Of course, the sides 10need not be straight but may be curved, providing parallelism isretained.

The splice means 15 is provided on both side members 10 to connect thesame where they abut along line 32. At each end of each wall 20 of eachside member 10 are formed two aligned openings 33 that are preferablyrectangular but, in any case, have elongated sides. A splice plate 34 ispositioned to span across the seam 32 and against the outer faces of thealigned walls 20'. Two embossments 35 in plate 34, one for each endopening in each wall 20, are entered into said openings, as in FIG. 4,and constitute keys that lock the trays against endwise separation. Thefit of embossments 35 in said openings 34 is preferably such that thereis substantially no end play between trays, nor looseness that wouldallow one tray to assume an angle relative to the other. Inwardly drawntapped embossments 36 are provided on plate 34 so they may enter theother two openings 33. An oval headed screw 37, engaged in saidembossments 36, locks the plate 34 in place, the heads of said screwsabutting the inner faces of tray walls 20.

The ends of the walls 20 may be each provided with three instead of twoopenings 33, and each end of each splice plate 34 may, accordingly, beprovided with two embossments 35 and a tapped embossment 36. The lattermay be preferably provided between the embossments 35. As to thementioned nicety of fit of embos ments 35 in openings 33, manufacturingtolerances should be taken into account to assure facility of assemblyor connection of adjacent trays, particularly as to longitudinal or endplay movement of the embossments 35 in the openings 33. While the tappedembossments are shown as entered into openings 33 with which aligned,the same may be outwardly directed so that only the shanks of screws 37pass through said openings. In this way, larger screw shanks may be usedto give maximum strength.

While the foregoing has illustrated and described what is nowcontemplated to be the best mode of carrying out the invention, theconstructions are, of course, subject to modification without departingfrom the spirit and scope of the invention. Therefore, it is not desiredto restrict the invention to the particular forms of constructionillustrated and described, but to cover all modifications that may fallwithin the scope of the appended claims.

Having thus described this invention, what is claimed and desired to besecured by Letters Patent is:

1. In a cable tray having transversely spaced longitudinal side membersand a plurality of transverse members spanning across the space betweenthe side members, means to connect each end of each transverse member toeach side member, said means comprising at least two end extensions onthe transverse member extending into and through the side member, and arolled bead on each extension in tight clinching engagement with theouter face of the side member.

2. In a cable tray according to claim 1, said two extensions beingdisposed on mutually normal planes, and the beads on the extensionsextending along said planes.

3. A cable tray comprising end-abutted tray sections,

said sections having longitudinal side members and said members, on eachside, being aligned, each side member, adjacent its abutting end, havingtwo longitudinally spaced openings therein, the four openings of twoabutted side 4 members being aligned, a splice plate disposed againstthe outer face of each side member, two embossments on each splice platein keying engagement in two of the aligned openings in the side members,and screws connecting each splice plate and the side members andextending through the other two openings.

4. A cable tray comprising endrabutted tray sections, said sectionshaving longitudinal side members and said members, on each side, beingaligned, each side member, adjacent its abutting end, having twolongitudinally spaced openings therein, the four openings of two abuttedside members being aligned, a splice plate disposed against the outerface of each side member, two cmbossments on each splice plate in keyingengagement in two of the aligned openings in the side members, andscrews connecting each splice plate and the side members and extendingthrough the other two openings, the splice plate being provided with twotapped embossments for said screws and the latter embossments extendinginto said latter two openings.

5. A cable tray comprising transversely spaced longitudinal sidemembers, said side members being formed with upwardly directed flangeslongitudinally extending from and along the lower marginal edges of saidmembers and in flatwise abutment with the inner faces of the sidemembers, a plurality of transverse members spanning the space betweenthe side members, means to connect each end of each transverse member toeach side member, said means comprising a plurality of spaced extensionsat each end of each transverse member, certain of said extensionsextending through the up-turned flange at the bottom of the side memberand through said side member, and another of said extensions beingseated upon the upper marginal edge of the up-turned flange andextending through the side member, certain of said extensions rbeingdistorted to abut the outer faces of said Gide members to secure saidparts against displacement.

References Cited in the file of this patent UNITED STATES PATENTS1,189,208 Hodkinson June 27, 1916 2,530,791 Smith Nov. 21, 19502,563,242 Hexdall Aug. 7, 1951 2,656,999 Ullberg Oct. 27, 1953 2,899,159Le Blang Aug. 11, 1959 2,905,416 Wiegand Sept. 22, 1959 2,917,259 HillDec. 15, 1959 2,938,692 Bosworth May 31, 1960 FOREIGN PATENTS 1,123,125France June 4, 1956

1. IN A CABLE TRAY HAVING TRANSVERSELY SPACED LONGITUDINAL SIDE MEMBERSAND A PLURALITY OF TRANSVERSE MEMBERS SPANNING ACROSS THE SPACE BETWEENTHE SIDE MEMBERS, MEANS TO CONNECT EACH END OF EACH TRANSVERSE MEMBER TOEACH SIDE MEMBER, SAID MEANS COMPRISING AT LEAST TWO END EXTENSIONS ONTHE TRANSVERSE MEMBER EXTENDING INTO AND THROUGH THE SIDE MEMBER, AND AROLLED BEAD ON EACH EXTENSION IN TIGHT CLINCHING ENGAGEMENT WITH THEOUTER FACE OF THE SIDE MEMBER.